At the present time, tray erectors having a well of fixed dimensions and a mandrel of fixed dimensions adapted to fit within the well, are used to erect corrugated cardboard or other packaging material trays or open topped cartons from a flat blank. The blank is positioned over the well and mandrel pushes on the blank in the base region to force the sides of the blank up as the blank is pushed into the well. Whilst this arrangement works well for trays of one fixed footprint size, if a tray of a different size is required, the components from which the well and mandrel are constructed must be repositioned or replaced to suit the dimensions of the new tray. Alternatively, more than one machine will be required. This adds to the cost of equipment or to the cost of operating the machine to allow for the erection of trays of various footprint dimensions.
Other forms of tray erector machines are known in the patent literature. Examples of such machines will be found in U.S. Pat. No. 3,882,655 (Monaghan) and U.S. Pat. No. 6,186,931 (Calvert, et al). It will be noted that the machines described in these United States patents are complex and do not allow for the erection of trays using a well/mandrel combination.